# OpenAI Models Sharply Improve Legacy Code Migration Capabilities > Source: > Published: 2026-10-20 18:25:55+00:00 OpenAI's latest models have made a groundbreaking leap in legacy code migration, achieving an impressive 86.6% accuracy with GPT-6.1 Sol, a significant jump from GPT-5.6 Sol's 5.4%, all while costing 39% less. This progress was measured using the innovative MultiLangBench benchmark, which pushes models to build a working database engine from scratch in 20 languages.